1. Field of the Invention
The present invention relates to a coloring matter compound, and an ink, a heat-sensitive transfer recording sheet and a resist composition for a color filter all containing the coloring matter compound.
2. Description of the Related Art
Recently, there have been increasing demands for image quality improvement for color images in a color liquid crystal display and the like. A color filter is an indispensable component that affects the performance in the image quality improvement of a liquid crystal display. Furthermore, in order to display or record full color images, color filters use coloring matters of the three primary colors of what is called additive color mixture or subtractive color mixture. Therefore, it is strongly desired to develop coloring matters that have absorption characteristics for realizing preferable color reproduction ranges and can endure various use conditions and environmental conditions.
For example, azo compounds have been widely used in a variety of fields including coating materials, inkjet inks and color filters. Among the azo compounds, a pyrazole azo compound has been conventionally used for color filters because the compound can be easily synthesized. Since the pyrazole azo compound is, however, a dye in general, light resistance thereof is low. For improving this property, a pyrazole azo compound prepared in the form of a pigment has been recently reported (see Patent Literatures 1 to 3). Although the light resistance becomes higher owing to characteristics of a pigment, there arises a problem in which saturation is lowered instead, and hence, it is desired to develop a coloring matter compound that is excellent in both light resistance and saturation.
Moreover, a coloring matter compound is desired to be improved in technical fields other than the field of color filters. An example of such fields includes a field of image formation employing a heat-sensitive transfer recording method.
The heat-sensitive transfer recording method is an image formation method by which recording is performed as follows: A heat-sensitive transfer sheet formed on a sheet-shaped substrate and including a coloring material layer containing a thermally migratory coloring matter is overlaid on an image receiving sheet having, on a surface thereof, a coloring matter receiving layer, and the heat-sensitive transfer sheet is heated so as to transfer the coloring matter included in the heat-sensitive transfer sheet onto the image receiving sheet. In this heat-sensitive transfer recording method, a coloring matter compound contained in a transfer sheet and an ink composition for the transfer sheet is an extremely significant material because this compound affects the speed of the transfer recording, image quality of recorded products, and storage stability. As a dye to be used in the heat-sensitive transfer recording method, methine disperse dyes such as C.I. Disperse Yellow 201, disazo disperse dyes such as C.I. Disperse Orange 13, and pyridone azo dyes have been proposed (see Patent Literature 4). These dyes have, however, a problem in which the light resistance is low, and even now, a coloring matter compound having further improved light resistance is desired to be developed.